Electric actuator

Abstract

The present invention comprises: a rod used as a rod-shaped member; an electroconductive polymer actuator having an electroconductive polymer that expands and contracts in a prescribed direction due to electric current; and an electromagnetic actuator having a fixed magnetic pole part in which the magnetic pole arrangement is fixed, and a variable magnetic pole part in which the magnetic pole arrangement is changed by switching of electric current, the fixed magnetic pole part and the variable magnetic pole part moving relative to each other due to the magnetic pole arrangement of the variable magnetic pole part being changed. The fixed magnetic pole part or the variable magnetic pole part is connected to the electroconductive polymer so that the relative movement direction of the fixed magnetic pole part and the variable magnetic pole part matches the expansion-contraction direction of the electroconductive polymer, and the rod is connected to the electroconductive polymer.

The invention claimed is: 
     
       1. An electric actuator comprising:
 a rod formed of a rod-shaped member; 
 a conductive polymer actuator having a conductive polymer that expands and contracts in a predetermined direction by an electric current, or a laminated electrostatic actuator having an electrode laminated element that expands and contracts in a predetermined direction by an electric current; and 
 an electromagnetic force actuator having a fixed magnetic pole portion in which a magnetic pole arrangement is fixed, and a variable magnetic pole portion in which the magnetic pole arrangement is changed by switching the electric current, and in which the magnetic pole arrangement of the variable magnetic pole portion is changed so that the fixed magnetic pole portion and the variable magnetic pole portion move relative to each other, 
 wherein any one of the fixed magnetic pole portion and the variable magnetic pole portion is connected to the conductive polymer or the electrode laminated element so that a relative movement direction thereof coincides with an expanding-contracting direction of the conductive polymer or the electrode laminated element, and 
 the rod is connected to the conductive polymer or the electrode laminated element, and the one of the fixed magnetic pole portion and the variable magnetic pole portion which are connected to the conductive polymer or the electrode laminated element. 
 
     
     
       2. The electric actuator according to  claim 1 , further comprising:
 a casing that accommodates the rod, 
 wherein one end side of the conductive polymer or the electrode laminated element in the expanding-contracting direction is connected to the casing, 
 the variable magnetic pole portion is fixed to the casing, 
 the fixed magnetic pole portion is connected to the other end side of the conductive polymer or the electrode laminated element in the expanding-contracting direction, and 
 the rod is connected to the fixed magnetic pole portion. 
 
     
     
       3. The electric actuator according to  claim 1 , further comprising:
 an electricity supply unit that supplies electricity to the conductive polymer actuator or the laminated electrostatic actuator, and the variable magnetic pole portion; and 
 a control unit that controls the electricity output from the electricity supply unit, 
 wherein when the rod is moved, the control unit controls the electricity supply unit to perform expansion and contraction of the conductive polymer actuator or the laminated electrostatic actuator simultaneously with relative movement between the variable magnetic pole portion and the fixed magnetic pole portion. 
 
     
     
       4. The electric actuator according to  claim 3 ,
 wherein when the movement of the rod is completed, the control unit controls the electricity supply unit to stop the relative movement between the fixed magnetic pole portion and the variable magnetic pole portion.